The Effects of Task Conditions on Trunk Muscular Fatigue during Dynamic Lifting

1994 ◽  
Vol 38 (10) ◽  
pp. 649-653
Author(s):  
Sang H. Kim ◽  
Min K. Chung ◽  
Wook G. Lee
Keyword(s):  
Low Frequency ◽  
Contralateral Side ◽  
The Body ◽  
Trunk Muscles ◽  
Heavy Load ◽  
Manual Lifting ◽  
Light Load ◽  
Trunk Musculature ◽  
The Individual ◽  
Task Conditions

To investigate the effects of MMH task conditions on the activity and fatigue of the trunk musculature, EMG signals from eight major trunk muscles were analyzed during 120 minutes of repetitive dynamic lifting tasks. Two independent task variables were the work strategy of weight and lifting frequency combination and the body posture. The dependent variables were the amplitude of EMG signals and the amount of median power frequency (MPF) decrease over time for the eight trunk muscles. The results of the study indicated that the recruitment and the level of force exertions of the trunk muscles during manual lifting tasks are a function of the direction and the weight of the external load. The different activities of the muscles due to given task conditions also influence the fatiguing process of the individual muscle. The muscles in the dorsal part of trunk were activated during the symmetric task conditions, while the muscles on the contralateral side to the workload were more strongly activated during the asymmetric task conditions. The decreasing trends of MPF were found in some activated muscles, and they were more pronounced for the asymmetric posture than for the symmetric posture. It was also seen that the muscles became fatigued faster for light load-high frequency conditions than for heavy load-low frequency conditions.

scholarly journals Optimized hip-knee-ankle exoskeleton assistance reduces the metabolic cost of walking with worn loads

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Gwendolyn M. Bryan ◽  
Patrick W. Franks ◽  
Seungmoon Song ◽  
Ricardo Reyes ◽  
Meghan P. O’Donovan ◽  
...  
Keyword(s):  
Body Weight ◽  
Muscle Activity ◽  
Metabolic Cost ◽  
Load Carriage ◽  
Heavy Load ◽  
Human In The Loop ◽  
Light Load ◽  
Wide Range ◽  
Ankle Exoskeleton ◽  
The Individual

Abstract Background Load carriage is common in a wide range of professions, but prolonged load carriage is associated with increased fatigue and overuse injuries. Exoskeletons could improve the quality of life of these professionals by reducing metabolic cost to combat fatigue and reducing muscle activity to prevent injuries. Current exoskeletons have reduced the metabolic cost of loaded walking by up to 22% relative to walking in the device with no assistance when assisting one or two joints. Greater metabolic reductions may be possible with optimized assistance of the entire leg. Methods We used human-in the-loop optimization to optimize hip-knee-ankle exoskeleton assistance with no additional load, a light load (15% of body weight), and a heavy load (30% of body weight) for three participants. All loads were applied through a weight vest with an attached waist belt. We measured metabolic cost, exoskeleton assistance, kinematics, and muscle activity. We performed Friedman’s tests to analyze trends across worn loads and paired t-tests to determine whether changes from the unassisted conditions to the assisted conditions were significant. Results Exoskeleton assistance reduced the metabolic cost of walking relative to walking in the device without assistance for all tested conditions. Exoskeleton assistance reduced the metabolic cost of walking by 48% with no load (p = 0.05), 41% with the light load (p = 0.01), and 43% with the heavy load (p = 0.04). The smaller metabolic reduction with the light load may be due to insufficient participant training or lack of optimizer convergence. The total applied positive power was similar for all tested conditions, and the positive knee power decreased slightly as load increased. Optimized torque timing parameters were consistent across participants and load conditions while optimized magnitude parameters varied. Conclusions Whole-leg exoskeleton assistance can reduce the metabolic cost of walking while carrying a range of loads. The consistent optimized timing parameters across participants and conditions suggest that metabolic cost reductions are sensitive to torque timing. The variable torque magnitude parameters could imply that torque magnitude should be customized to the individual, or that there is a range of useful torque magnitudes. Future work should test whether applying the load to the exoskeleton rather than the person’s torso results in larger benefits.

Escape Responses of Herring Larvae to Visual Stimuli

1989 ◽  
Vol 69 (3) ◽  
pp. 647-654 ◽  
Author(s):  
R.S. Batty
Keyword(s):  
Startle Response ◽  
Larval Fish ◽  
Fish Larvae ◽  
Adult Population ◽  
Juvenile Fish ◽  
Reciprocal Inhibition ◽  
Contralateral Side ◽  
The Body ◽  
Different Types ◽  
Trunk Musculature

Predation is now considered the main cause of mortality in larval and juvenile fish (Hunter, 1984) and is therefore the most important factor controlling recruitment to the adult population. Marine fish larvae are prey for many different types of predator including medusae, crustaceans and larger fish. When predatory attacks are sensed both adult and larval fish may respond by making a 'C-start', a very fast, simultaneous contraction of the trunk musculature that deforms the body into a C-shape within 20 ms (Eaton & Hackett, 1984). This startle response is mediated by the Mauthner cells, a pair of prominent neurones in the hind brain or by other reticulo-spinal cells located in the same region. As a result of reciprocal inhibition and decussation of the cell axon, stimulation on one side of the body results in contraction of all the muscle on the contralateral side.

Estimation of EMG activity of trunk muscles in manual lifting tasks based on trunk dynamics using the fuzzy relational rule network

2003 ◽  
Author(s):  
Waldemar Karwowski ◽  
Adam Gaweda ◽  
William S. Marras ◽  
Kermit Davis ◽  
Jacek Zurada
Keyword(s):  
Trunk Muscles ◽  
Emg Activity ◽  
Manual Lifting

Influence of stable iodine on the uptake of the thyroid – model vs. experiment

2001 ◽  
Vol 40 (01) ◽  
pp. 31-37 ◽  
Author(s):  
U. Wellner ◽  
E. Voth ◽  
H. Schicha ◽  
K. Weber
Keyword(s):  
Time Course ◽  
Compartment Model ◽  
The Body ◽  
Iodine Uptake ◽  
Model Calculations ◽  
Physiological Conditions ◽  
Iodine Supply ◽  
Predicted Values ◽  
The Individual ◽  
Stable Iodine

Summary Aim: The influence of physiological and pharmacological amounts of iodine on the uptake of radioiodine in the thyroid was examined in a 4-compartment model. This model allows equations to be derived describing the distribution of tracer iodine as a function of time. The aim of the study was to compare the predictions of the model with experimental data. Methods: Five euthyroid persons received stable iodine (200 μg, 10 mg). 1-123-uptake into the thyroid was measured with the Nal (Tl)-detector of a body counter under physiological conditions and after application of each dose of additional iodine. Actual measurements and predicted values were compared, taking into account the individual iodine supply as estimated from the thyroid uptake under physiological conditions and data from the literature. Results: Thyroid iodine uptake decreased from 80% under physiological conditions to 50% in individuals with very low iodine supply (15 μg/d) (n = 2). The uptake calculated from the model was 36%. Iodine uptake into the thyroid did not decrease in individuals with typical iodine supply, i.e. for Cologne 65-85 μg/d (n = 3). After application of 10 mg of stable iodine, uptake into the thyroid decreased in all individuals to about 5%, in accordance with the model calculations. Conclusion: Comparison of theoretical predictions with the measured values demonstrated that the model tested is well suited for describing the time course of iodine distribution and uptake within the body. It can now be used to study aspects of iodine metabolism relevant to the pharmacological administration of iodine which cannot be investigated experimentally in humans for ethical and technical reasons.

Ayurveda dietary guidelines during Covid-19 Pandemic

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1477-1481
Author(s):  
Ishwari Gaikwad ◽  
Priyanka Shelotkar
Keyword(s):  
Dietary Habits ◽  
Relevant Literature ◽  
Dietary Guidelines ◽  
The Body ◽  
Daily Regimen ◽  
Web Page ◽  
Healthy State ◽  
Health Disorders ◽  
The Individual ◽  
The Right

The current world situation is both frightening and alarming due to the massive disruption caused by the Covid-19 pandemic. The next few days are censorious as we need to be very precautious in our daily regimen as well as dietary habits. Ayurveda offers knowledge about food based on certain reasoning. Indecent food custom is the chief cause for the rising development of health disorders in the current era. In classical texts of Ayurveda, the concept of diet explained well, ranging from their natural sources, properties and specific utility in pathological as well as physiological manner. In this work, the review of the relevant literature of Ahara (Diet) was carried out from Charak Samhita and other texts, newspapers, articles, web page related to the same.  Every human being is unique with respect to his Prakriti (Physical and mental temperament), Agni (Digestive capacity), Koshtha  (Nature of bowel) etc. For that reason, the specificity of the individual should be kept in mind. Ahara, when consumed in the appropriate amount at the right moment following all Niyamas (Guidelines) given in Ayurveda texts, gives immunity and keeps the body in a healthy state during pandemics such as Covid-19. Ultimately, this will help the human body to maintain its strength for life. This article reviews the concept of diet viz. combination of foods, their quantity and quality, methods of preparation and processing, which are to be followed during pandemics and are essential in maintenance and endorsement of health and preclusion of diseases.

Physiological and Hereditary Hyperbilirubinemia in Athletes: Role in Reducing Efficiency and Correction Methodology

2020 ◽  
Vol 5 (5) ◽  
pp. 386-393
Author(s):  
L. M. Gunina ◽  
◽  
Kazys Mylashyus ◽  
Voitenko V. L. ◽  
◽  
...  
Keyword(s):  
Physical Activity ◽  
Functional State ◽  
Oxygen Demand ◽  
Diagnostic Algorithm ◽  
Drug Prevention ◽  
The Body ◽  
Erythrocyte Membranes ◽  
Pharmacological Agents ◽  
Bilirubin Metabolism ◽  
The Individual

Under high-intensity loads, the athlete's bodies take place a number of biochemical reactions and physiological processes that can lead to hyperbilirubinemia. The factors that can initiate the onset of this phenomenon include the syndrome of micro-damage muscle, violation of the integrity of erythrocyte membranes, decreased blood pH, malnutrition and increase oxygen demand of the body. Degree of expression of manifestations of physiological bilirubinemia depends on the level of adaptation of the athlete to the physical activities offered. Hyperbilirubinemia in athletes can be one of the components of the deterioration of the functional state, forming the symptoms of endogenous intoxication. The relevance of this problem in sport lies in the relatively low detection rate of hyperbilirubinemia due to the lack of regular screening studies. However, in drawing up a plan of nutritional- metabolic support for training and competitive activity and recovery measures, must not only the individual reaction of the athlete body to physical activity, but also the severity of shifts in the indicators of bilirubin metabolism and their ratio. The article describes the reasons for the increase in bilirubin levels, which can be caused by both the effect of physical activity and by the presence of pathological processes in athletes. The factors influencing the blood serum’s bilirubin content are also highlighted, which include the state of erythrocyte cell membranes and the rate of hemoglobin destruction, the functional state of the liver, the specifics of physical loads and the use of ergogenic pharmacological agents by athletes. Particular accent has been placed on the illumination of hereditary hyperbilirubinemias, which may have been detected at the stage of selection of athletes. The most common phenomenon is Gilbert's syndrome, which occurs in 2-5% of cases in the general population, is characterized in the clinic by a benign flow and is manifested by episodes of jaundice and an increase in total bilirubin content to moderate values due to indirect. The frequency of detection of hyperbilirubinemias in the population of athletes is 4.68%, among which Gilbert's disease accounts for almost half (48.7%). Conclusion. The work highlighted the pathogenesis and diagnostic algorithm of Gilbert's disease, and also emphasized that its drug prevention and correction in athletes to maintain functional and physical fitness should be carried out taking into account anti-doping rules, which requires upon diagnosis timely receipt of a therapeutic exclusion

Study on Pramana Shareera in relation to Prakriti

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Rajendra Pai N. ◽  
U. Govindaraju
Keyword(s):  
Observational Study ◽  
Upper Limb ◽  
Lower Limb ◽  
Characteristic Property ◽  
The Body ◽  
Artificial Limbs ◽  
Body Parts ◽  
Unit Of Measurement ◽  
The Individual ◽  
Different Parts

Ayurveda in its principle has given importance to individualistic approach rather than generalize. Application of this examination can be clearly seem like even though two patients suffering from same disease, the treatment modality may change depending upon the results of Dashvidha Pariksha. Prakruti and Pramana both used in Dashvidha Pariksha. Both determine the health of the individual and Bala (strength) of Rogi (Patient). Ayurveda followed Swa-angula Pramana as the unit of measurement for measuring the different parts of the body which is prime step assessing patient before treatment. Sushruta and Charaka had stated different Angula Pramana of each Pratyanga (body parts). Specificity is the characteristic property of Swa-angula Pramana. This can be applicable in present era for example artificial limbs. A scientific research includes collection, compilation, analysis and lastly scrutiny of entire findings to arrive at a conclusion. Study of Pramana and its relation with Prakruti was conducted in 1000 volunteers using Prakruti Parkishan proforma with an objective of evaluation of Anguli Pramana in various Prakriti. It was observed co-relating Pramana in each Prakruti and Granthokta Pramana that there is no vast difference in measurement of head, upper limb and lower limb. The observational study shows closer relation of features with classical texts.

Epilogue

2017 ◽  
Author(s):  
Joshua S. Walden
Keyword(s):  
The Body ◽  
The Self ◽  
The Individual ◽  
Relationship Of ◽  
The Relationship

The book’s epilogue explores the place of musical portraiture in the context of posthumous depictions of the deceased, and in relation to the so-called posthuman condition, which describes contemporary changes in the relationship of the individual with such aspects of life as technology and the body. It first examines Alfred Hitchcock’s Vertigo to view how Bernard Herrmann’s score relates to issues of portraiture and the depiction of the identity of the deceased. It then considers the work of cyborg composer-artist Neil Harbisson, who has aimed, through the use of new capabilities of hybridity between the body and technology, to convey something akin to visual likeness in his series of Sound Portraits. The epilogue shows how an examination of contemporary views of posthumous and posthuman identities helps to illuminate the ways music represents the self throughout the genre of musical portraiture.

scholarly journals Slithering CSF: Cerebrospinal Fluid Dynamics in the Stationary and Moving Viper Boa, Candoia aspera

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 672
Author(s):  
Bruce A. Young ◽  
Skye Greer ◽  
Michael Cramberg
Keyword(s):  
Cerebrospinal Fluid ◽  
Cardiac Cycle ◽  
Low Frequency ◽  
Mean Amplitude ◽  
The Body ◽  
Body Waves ◽  
Lower Amplitude ◽  
Lateral Undulation ◽  
Recovery From Anesthesia ◽  
The Relationship

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.

Embodying the culture of achievement: Culture between illness and perfection is a ‘thin line’ – obtaining the ideal female body as an act of achievement

2021 ◽  
pp. 1354067X2110040
Author(s):  
Josefine Dilling ◽  
Anders Petersen
Keyword(s):  
Experimental Study ◽  
Human Body ◽  
Female Body ◽  
The Body ◽  
Thin Line ◽  
Complex Processes ◽  
The Individual ◽  
Different Levels ◽  
The Ideal ◽  
Body Ideals

In this article, we argue that certain behaviour connected to the attempt to attain contemporary female body ideals in Denmark can be understood as an act of achievement and, thus, as an embodiment of the culture of achievement, as it is characterised in Præstationssamfundet, written by the Danish sociologist Anders Petersen (2016) Hans Reitzels Forlag . Arguing from cultural psychological and sociological standpoints, this article examines how the human body functions as a mediational tool in different ways from which the individual communicates both moral and aesthetic sociocultural ideals and values. Complex processes of embodiment, we argue, can be described with different levels of internalisation, externalisation and materialisation, where the body functions as a central mediator. Analysing the findings from a qualitative experimental study on contemporary body ideals carried out by the Danish psychologists Josefine Dilling and Maja Trillingsgaard, this article seeks to anchor such theoretical claims in central empirical findings. The main conclusions from the study are used to structure the article and build arguments on how expectations and ideals expressed in an achievement society become embodied.

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